Cerebral ischaemic changes in association with the severity of ICA lesionsand cerebropetal flow

Objectives: to study the effect of the severity of internal carotid artery (ICA) lesions on cerebral haemodynamics. Design: cross-sectional study. Materials and methods: magnetic resonance (MR) imaging, angiography (MRA) a nd spectroscopy (MRS) were used to study the prevalence of (border-zone) in farctions, volume flow in the main cerebropetal and middle cerebral arterie s (MCA) and metabolic changes in the MCA territories in 170 patients with s ymptomatic ICA stenoses or occlusions and 25 control subjects. Results: no significant correlation was found between severity of the carot id lesion and the prevalence of border-zone infarctions. Also, no significa nt correlation tons found with changes in the N-acetyl-aspartate/choline ra tio nor with the prevalence of cerebral lactate. In patients with at least one severe ICA lesion, pow in the basilar artery was increased. Flow in the MCA on the symptomatic and asymptomatic side was decreased when at least o ne ICA was occluded. Total cerebropetal flow, (flow through the ICAs plus b asilar artery) was decreased when at least one ICA was occluded. No signifi cant correlation was found between changes in cerebropetal flow and the N-a cetyl-aspartate/choline ratio nor with the prevalence of border-zone infarc tions. Conclusion: border-zone infarctions and ischaemic metabolic changes are Mot directly the result of cerebral hypoperfusion caused by severe ICA lesions .